I am so glad you replied..since i am not moving ahead..
I am based in India. The pump is locally manufactured and the data i shared was received from the manufacturer (rather , the seller)
Currently i do not have an intricate pipeline installed above the pump.I pull water from a tank and throw it back in again.To create pressure, i have a valve which stops the water-flow to show a reading on a gauge (optimum pressure was 12kg/cm2)
I too am not an expert in pumps/motors. so please bear with me.
The actual utilisation will be in a submerged tube-well below ground (300ft).
To maintain a constant v/f ratio, i calculate motor voltage as Vsol/root2 x duty
and based on this parameter i define a frequency 0- 50Hz.
Does this all make any sense, or something wrong?
EDIT : A little search shows that you are right.The pump
is a centrifugal pump
When i pull the pump out of water (with a chain-pulley arrangement) to make it seem like a dry run situation, what happens is ..
Since there is no load on the drive, input solar current reduces, but o/p ac voltage is increased
(you said you read about the algorithm i am following with Northguy) and the motor starts demanding more current.
I thought that actually the current should have reduced, but it did not